Mobile devices are ubiquitous. The ways to interact with them and the ways mobile devices behave have evolved over time. One important technology for mobile devices is their sensing capabilities. Sensing can occur via many modalities, such as haptic/pressure sensing, audio sensing, light/vision sensing, temperature sensing, and capacitive sensing. Not only can these modalities allow us to interact with the mobile device in a myriad of different ways, these modalities allow the mobile device to become “smarter” such that the mobile devices can better understand contexts and the way users are interacting with the mobile devices.
One interesting modality is capacitive sensing. Capacitive sensing has been used with touch screens for some time to allow user to provide user input via the screen of a mobile device without the use of physical buttons. In some applications, capacitive sensing on a large surface/skin can even be used for sensing grip or hand postures. In some other applications, two electrodes can be provided, one on each side of a mobile device for whole hand recognition. In yet some other applications, an electrode can be provided adjacent to an antenna to detect the presence of a finger or hand in close proximity to the antenna.